Chemical products and processes for producing same



Patented is... s, 1 31 I CHEMICAL PRODUCTS AND PROCESSES FOR PRODUCINGSAME Wallace H. Car'others, Arnold M. Collins, and James E; Kirby,Wilmington Del, assignorl to E. I. du Pont de Nemours 8: Company,Wilmington, DeL, a corporation oi Delaware No Drawing. ApplicationFebruary 6, 1935,

f Serial No. 5,246

'25 Claim.

This invention relates to a process of polymerizingchloro-2-butadiene-l,3. More particularly it relates to thepolymerization of chloro-2-buta- Ilene-1,3 in the presence of otherpolymerizable I materials. Still more particularly it relates to thepolymerization of chloro-2-butadlene-1,3 in the presence of otherbutadienes'.

. This application is a continuation in part or a (appendingapplication, Serial No. 665,554, filed 10 April 11, 1933 and of anapplication serial No. 519,242, filed February 28, 1931, and now maturedinto. Patent #1967360. It is an object of this invention to produce newpolymers of chloro-2-butadiene-L3. It is a fur- 15 ther object of theinvention to produce new polythem of chloro-2-butadiene-1 ,3 bypolymerizing chloro-z-butadiene-Lil in the presence of other butadienes.It is a still further object of the inventlon to carry out thepolymerization of chloro- 2-butadiene-L3 in the presence of otherbutadlenes in various media. A still further object of the invention isto provide a means for imparting to the polymers ofchloro-2-butadienes-l,3 some of the properties of the polymers of otherbutadienes. Other objects will appear hereinafter.

. These objects are accomplished by the following invention in whichchloro-2-butadiene-l,3 is

polymerized in the presence of other butadienes.

This polymerization is brought about both in the presence and absence ofother solvents or diluents,

as well as in aqueous dispersions of the two materials which may or maynot contain, in addition v to these materials, modifying ingredients. 1The proportions of the two materials used vary widely as do theproperties of the, products.

The invention is more fully illustrated by the following examples. Theseexamples, however,

are intended to be illustrative only and are not to be construed aslimiting the scope of the inven- 40 tion.

Example 1 55 Parts Polymer 100 Phenyl-p-naphthylamine 1.5 Zinc oxide10.0 Benz 1.0

60 Stearic a (or. zoo-z) The cured polymer remained pliable for morethan five weeks at 10C.

Example 2 One volume of chloro-2-butadiene-L3 and one I volume ofisoprene are mixed and sealed in a vessel containing two volumes air.The mixture is allowed to stand for three months and thenis opened. Theproduct is a colorless, transparent, strong. very extensible,- elasticmass. It 10 still contains some unchanged isoprene which graduallyevaporates when a sample is freely exposed to the air.

In the following examples the use of other butadienes in thepreparationoi synthetic latices from chloro-2-butadiene-l.3 isillustrated.

sample 3 A solution of grams of dimethyl-2.3-butadime-1,3 in 90 grams ofchloro-2-butadiene -l,3 was emulsified in 100 grams of 2% sodium oleatesolution. The emulsion was stored at C. for 45 hours, after which it wasfound to be substantially completely polymerized to the elastic stage.Phenyl-p-naphthylamine (1.5% on the polymer 25 'content) was then addedin the form of an aqueous dispersion to act asap anti-oxidant for thepolymers. A film was flowed ona porous plate. Aiter most of the waterhad soaked into the plate there remained a film oi rubber-like polymer.The drying was completed by heating the film at, 80 C. for 48 hours. Thefinished product was a film resembling soft vulcanized rubber. This filmhad a. tensile strength of 1100 lbs/in. and an elongation of l300%. Itremained pliable during prolonged storage at 10 0.

Example 4 v A solution of 1 gram of heptyl il-butadiene-ia(CH2=C(C'1H15)--CH=CHz) in 9 grams of chloro- 4o 2-butadiene-1,3 wasemulsified in 10 grams of 2% sodium oleate solution. The emulsion wassubstantially completely polymerized to the elastic stage, stabilizedand a film prepared as in Example 3. This product was fairly strong andelastic and resembled soft vulcanized rubber. It had bettertearresistance and pliability than films from emulsions oichlorobutadlene.

' Example 5 7 A solution of 1 gram-oi 'bromo-iZ-butadiene-L3 in 99 gramsof chloro-2- butadiene-L3 was emulsified in 100 grams or 2% sodiumoleate'solution and the emulsion stored in an ice bath. After 5 hours,34.4% of the mixture of dienes had polymerized; The emulsion wastransferred to a refrigerator at 10 C. and stored-for an additionalperiod of 43 hours. The-emulsion, now completely polymerized, wasstabilized as in the above examples and films prepared in the samemanner.

2100 lbs/in. and better tear resistance than films from emulsions ofchlorobutadiene alone.

Example 6 An emulsion was prepared which was similar in every way tothat of Example 5, except that 10 grams of bromo-2-butadiene-1,3 and 90grams of chloro-2-butadiene-1,3 were used. The emulsion polymerized muchmore rapidly (51.25% in 5 hours) but the product was very similar.

. Example 7 Thirty parts of butadiene are dissolved in 70 parts ofchloroprene contained in a thoroughly cooled vessel, and the resultingmixture is slowly added to 100 parts of water containing two parts ofsodium oleate, the solution being vigorously stirred with a mechanicalstirrer during the addition and the temperature being maintained betweenand C. In this manner a smooth homogeneous milk-like dispersion isobtained. It is placed in a closed vessel and allowed to stand at atemperature between and C. for 1-2 weeks. During this period of time themixture of dienes is largely polymerized. The resulting latex can becoagulated, by the addition of acid. The coagulum of synthetic rubber ismuch softer and more plastic and pliable than products similarlyprepared from chloro-2-butadiene-1,3 alone. On the other hand, in itselastic properties and strength it is superior to products ordinarilyobtained from butadiene alone. In carrying out the preparation of amixedpolymer by this method the rate of polymerization is considerably slowerthan that obtained when using chloro-2- butadiene-1,3 alone. It may,therefore, be desirable to accelerate the reaction either by theaddition of such catalysts as hydrogen peroxide or other peroxides, orby the use of a somewhat higher temperature. The synthetic latex of thisprocess may be stabilized by the addition of ammonia and antioxidants inthe usual manner, and it may then be used for the preparation of shapedarticles by dipping or for the coating of fabrics such as cloth. Thecoagulated polymer also may be mixed with the usual types of rubbercompounding ingredients and converted into a less plastic and moredefinitely vulcanized form by heating at elevated temperatures, forexample, 125 C.

It will be observed that in Examples 3 and 4 the chlorobutadienepolymerized completely to an elastic polymer and rubber articlesprepared from these synthetic latices, like those from chlorobutadienealone, required no vulcanization and the modified rubber retained thedesirable properties previously set forth. These latices are admirablysuited to the preparation of coated and impregnated cloth and paperbecause of the softness and pliability of the synthetic rubber. Althoughwe do not wish to be limited to theory, we attribute the improvement inpliability in the processes of the above examples to an actual-chemicalintercombination of chlorobutadiene with the added substance, resultingin a chemically and physically different molecule.

In general the process of the present invention comprises thepolymerization of chloro-2-butadiene-1,3 in the presence of a widevariety of butadienes under rather widely varying conditions. Each ofthese materials in the presence of which chloro-2-butadiene-1,3 is to bepolymerized will,

These rubber like films had a tensile strength of I as the namebutadiene", implies, be found to contain the following nucleus in anopen chain:

The compounds included by this group will, therefore, vary frombutadiene, the simplest member. through a great number of substitutedbutadienes containing a diversity of substituents. Other examples ofsuch butadienes are brom'odbutadiene-1,3 and chloro-1-butadiene-1,3aswell as those described in the following United States patents andapplications: United States Patent No. 1,950,440; United States PatentNo. 1,950,441; and United States Patent No. 1,963,108, also anapplication of Carothers, Serial No. 583,391, filed December 26, 1931,and an application of Carothers and Berchet, Serial No. 640,326, filedOctober 29, 1932. s

It has been found that particularly desirable products are obtained bypolymerizing chloro-2- butadiene-13in the presence of lower members ofthe various series of butadienes mentioned, as for example,dimethyl-2,3-butadiene-l,3, bromo- 2-butadiene-1-, 3,heptyl-2-butadiene-1,3, ethyl-2- butadiene-1,3,' methyl-l-butadiene-lj,2,3-diethyl-butadiene-1,3, octadiene-Zi,5 cyclo-pentadiene, the isomerof cyclo-hexadiene containing conjugate unsaturation anddimethyl-1,l-butadiene-1,3.' The preferred procedure, however, involvesthe polymerization chloro-2-butadie'ne- 1,3 in the presence of other2-substituted butadienes and, in particular, 2-substitutedbutadienes-1,3 of the general formula where Y may, for example, bealkyL; aryL.

aralkyl, alkoxy, bromine, iodine, etc. Particular examples of suchbutadienes, in addition to those already mentioned, includephenyl-Z-butadiene- 1,3, methoxy-2-butadiene-l,3, ethoxy-Z-butadione-1,3and butoxy-2-butadiene-l,3.

It has been stated that an object of this invention is to provide ameans for imparting to.

It is not possible to draw any exact generaliaations concerning theproperties of these products but it may be said that'when polymerizedchloro- 2-butadiene-1,3 preponderates or more) the products are usuallyrubber-like, but if the added ingredients are present in large amountsthe product will reseinble the polymers of those ingredients, exceptthat it has a toughness and elasticity similar to that of polymerizedchloro-2- butadiene-1,3. It is, therefore, apparent that the particularproportions to be used will in each case depend upon the propertieswhich are desired in the final product.

Although the proportions of the various constituents exhibit a markedinfluence on the final product they do not completely determine itsproperties which are dependent as well on the conditions of thepolymerization. Two general methods of polymerization, namely, inbulkand in emulsion'are illustrated by the examples and to these may beadded a third, namely, polymerization in the presence of a solvent fortherchloro- 2-butadiene-l,3 and the other butadiene. As might beexpected, in general, the polymerization takes place in emulsion at amore. rapid rate and in solution at a less rapid rate than when thepolymerization is carried out in the absence of a diluent or a solventas is the case with chloro-2- butadiene when it is polymerized alone.The rate of polymerization is increased by catalysts, such as benzoylperoxide, and is decreased by inhibitors, such asphenylbetanaphthylamine. The rate of polymerization is favorablyaffected by ordinary light and to an even greater extent by ultravioletlight. Higher temperatures and pressures, likewise, favor higher ratesof polymerization. Temperatures in the range of to 30 C.

are mentioned in the examples and, although,

dition of suitable solvents, both high andlow boiling, acid acceptorssuch as proteins, catalysts, inhibitors, etc.

Time is an important factor in both the first polymerization step andthe curing. The examples indicate that the time of exposure to thepolymerizing influence is by nomeans fixed, although the'time ofexposure does, to a large ex-' tent, determine the properties oftheflnal product. No exact times can be given, however, in view of. thefact that the stage of polymerization reached in a given time dependsalso to Ialarge extent on other factors discussed herein. The timerequired to produce a given productcan, of course, be determined bypolymerizing a test sample under selected conditions and observing thenature of the product at frequent intervals as will be obvious to oneskilled in the art.

Various materials, other than the butadienes may be present during thepolymerization as has been partly pointed out hereinbefore. Other 3modifications include polymerization in dispersion media other thanwater, in solvents for the two monomers which are not solvents for the.polymerized product, in the presence of other film-forming materials orpaint or varnish adjuncts as for example, natural or synthetic resins,cellulose derivatives, drying'oils, etc.

While the rate of polymerizationappears to be favorably affected by thepresence of oxygen, polymerization may be carried out in the substantialabsence of oxygen. Interesting variations in the final product may inthis way be produced.

In the preparation of emulsions as described above, the invention is notlimited to theemulsifying agent already mentioned nor to the quantitiesemployed in the example; Any emulsification agent appears to functionsatisfactorily when used in sufficient quantity. In addition to thosealready named, the fat alcohol sulfates or sulfonates or theirderivatives or the alkyl naphtha:

lene sulfonic acids as well as the quaternary am-' monium salts,containing long chain saturated hydrocarbon radicals and relatedcompounds will be found to function satisfactorily. The quantity of eachto be used may, in general, be determined r from their knowneffectiveness in other similar uses.

While still operating within the scope of the present invention, itshould be apparent, from the description, that it is possible to preparefinal products differing widely in properties. The wide difference makesit difficult to generalize but among others it is possible to produceproducts varying from viscous liquids, through plastic masses to toughelastic or brittle masses. Preferably, however, the invention is carriedout, as illustrated in the examples, by continuing the polymerizationonly to the plastic stage and-then separating the plastic mass from theunpolymerized material or any other undesired material and thereaftereither with or without the addition of compounding ingredients, carryingthe polymerization on to the desired final stage, usually an elasticproduct. It has been possible to show in some cases, actualinter-polymerization but the invention is not limited to such a result.

The above remarks apply where the product is to be used in the massiveform. The mass may, however, be dissolved in a suitable solvent, or thesolution or dispersion resulting from carrying out the polymerization inemulsion or solution may be employed in a variety of ways, for example,as rubber substitutes for the preparation of dipped. coated, extruded orimpregnated articles or films may be cast from theliquid composition.

The polymer product may also be given further treatment to produce otherproducts, also useful in a variety of ways. By way o-f'example, thepolymers may be halogenated or may be reacted with a hydrohalogen undera variety of conditions, i. e., in solution, in the gaseous state or inthe liquid state.

Certain of the polymers are characterized by excellent softness andpliability and are therefore eminently suited to particular uses. Forexample, they may be calendered on to cloth for the preparation ofcoated fabrics of excellent quality, since they retain the properties oflong lifeand resistance to various solvents and reagents which arecharacteristic of polymers, of pure chloro-2-butadiene-1,3. Solutions ofthe uncured polymers in benzene, toluene or other suitable solvents maybe used for coating and impregnating by any of the numerous processesset forth in the copending application of Collins and Larson, Serial No.572,727, filed November 2, 1931. Further, the polymers may be compoundedwith re-enforcing agents, such as carbon black,

to produce further useful products.

The invention has been described with particular reference tochloro-2-butadiene-1,3 but it should .be apparent that the remarksalready' made with regard to thechloro compound apply, in general, toother halogen-2-butadienes-1,3, for

- example,.-bromo-2-butadiene-1,3. Thus, the latcleus I l in an openchain is used it is intended to include.

A as obvious equivalents, closed chain compounds 01 the type ofcyclo-penta-diene. In reality the term "in an open-chain" is used onlyto distinguish the compounds to which the present invention relates fromaromatic compounds which do contain the same nucleus. The realdistinction is between aliphatic and aromatic compounds. Compounds ofthe type of cyclo-penta-diene, to which the broad term alicyclic" isapplied are classified with aliphatic compounds in the art and are notintended to be excluded by the terms of the claims of this application.

In applying the products of this invention it is often desirable toadmix them with pigments, dyes, antioxidants, or other modifying agents,and the use of such ingredients will be obvious to those skilled in theart relating to rubber, resins,

gums, drying oils, etc.

It is apparent that many widely diiferent embodiments of this inventionmay be made without departing from the spirit and scope thereof andtherefore it is not intended to be limited except as indicated in theappended claims.

We claim:

1. A polymer of chloro-2-butadiene-1,3 obtainable by polymerizingchloro-2-butadiene-l,3 in the presence of'a second compound containingthe nucleus L J; (I:

in an open chain.

2. An elastic polymer of chloro-2-butadiene-1,3 obtainable bypolymerizing chlOro-Z-butadiene- 1,3 in the presence 01' a secondcompound containing the nucleus reach in an open chain.

3. A plastic polymer of chloro-2-butadiene-l,3 obtainable bypolymerizing chloro-2-butadiene- 1,3 in the presence of a secondcompound containing the nucleus in an open chain.

4. A product obtainable by partially polymerizing chloro-2-butadiene-1,3in the presence of a second compound containing the nucleus sa es.

in an open chain.

6. The process which comprises completely polymerizingchlor-2-butadiene-1,3 in the presence of a second compound containingthe nu- 01' a second compound containing themucleus in an open chain andthen separating a plastic mass from the unpolymerized material.

8. The process which comprises partially polymerizingchloro-2-butadiene-1,3 in the presence of asecond compound containingthe nucleus in an open chain, then separating a plastic mass from theunpolymerized material and thereafter heating the plastic mass at about125 C. until cured.

9. The process which comprises dispersing, in water,chioro-2-butadiene-1,3 and a second compound containing the nucleus inan open chain and thereafter polymerizing the chloro-2-butadiene-1,3 inthe dispersed state.

10. The process which comprises polymerizing chloro-2-butadiene-1,3 inthe presence of a second compound containing the nucleus in an openchain and in the presence of a solvent i'or the two materials.

11. The process which comprises in water, chloro-2-butadiene-L3 and asecond compound containing the nucleus in an open chain, thenpolymerizing the chloro-2- butadiene-1,3 in the dispersed state andthereafter separating the polymer from the dispersing medium.

12. The process which comprises polymerizing chloro-2-butadiene-L3 inthe presence of a second compound containing the nucleus in an openchain, in the presence of a solvent for the two materials and thenseparating the polymer from the solvent.

13. A polymer of a halogen-2-butadiene-L3, obtainable by polymerizing ahalogen-2-butadiene-1,3 in the presence of a second compound containingthe nucleus in an open chain. 14. The process which comprisespolymerizing a halogen-Z-butadiene-Lil in the presence of a secondcompound containing the nucleus in an open chain.

15. A polymer 01' a halogen-2-butadiene-L3, obtainable by polymerizing ahalogen-2-butadiene-1,3 in the presence of a second 2-substitutedbutadiene-1,3..

16. A polymer oi chloro-2-butadiene-1,3, obtainable by polymerizingchloro-2-butadiene-13 in the presence of a second Z-substitutedbutadiene-1,3.

17. A polymer of chloro-2-butadiene-1,8, obtainable by polymerizingchloro-Z-butadiene-LS in the presence of butadiene-1,3.

18. A polymer of chloro-2-butadiene-1,3, obtainable by polymerizingchioro-z-butadiene-m in the presence of dimethyl-2,3-butadiene-1.3.

19. A polymer oi chloro-2-butadiene-L3 obtainable by polymerizingchloro-2-butadiene-l,3 in the presence of methyl-2-butadiene-1,3.

20. The process which comprises polymerizing chloro-2-butadiene-L3 inthe presence of dimethyl-2,3-butadiene-L3 and in the presence of apolymerization catalyst at about room temperature.

21. The process which comprises dispersing chloro-2-butadiene-1,3 andbutadiene in an aqueous solution containing an emulsifying agent andpolymerizing the oh1oro-2-butadiene-1,3 in the emulsified state at aboutroom temperature.

22. The process which comprises polymerizing chloro-2-butadienel,3 inthe presence of methyl-2-butadiene-L3 and in the presence of apolymerization catalyst at about room temperature.

23. A polymer of chloro-2-butadiene-1,3 obtainable by polymerizingchloro-2-butadiene-1,3 in the presence of a second compound 01 thegeneral formula CH1=CYCH=CH2, in which Y is a radical selected from thegroup consisting of alkyl, ,aryl, arylalkyl, alkoxy, bromine and iodineradicals.

24. A polymer as described in claim 23, further characterized in that Yin the general formula is a low molecular weight radical.

25. A dispersion obtainable by dispersing, in water,chloro-2-butadiene-l,3 and a second compound containing the nucleusWALLACE H. CAROTHERS ARNOLD M. COLLINS. JAMES E. mRBY.

